The cryolite-aluminum oxide aluminum fusion electrolysis is the only aluminum production method in the aluminum industry all the time. As for the current Hall-Herout electrolytic cell, the electrolytic temperature commonly is often 940-960° C.; the comprehensive electric power consumption is 13.5 kw-15.0 kW·h/kg (A1); and the power efficiency is less than 50%. At the same time, large quantity of greenhouse gasses, such as CO2 and CFn, and carcinogenic substances are generated, resulting in severe environmental pollution. The development of the aluminum industry is seriously limited by the large energy consumption, resource consumption, environmental load and so on. The energy saving, consumption reduction and pollution reduction are development directions of the aluminum industry in the future.
The replacement of carbon anode with the inert anode not only saves anode carbon consumption of 400 kg-500 kg/t·Al (the carbon anode accounts for 12%-15% of production cost of aluminum), but also reduces the carbon tax brought by the emission of equivalent CO2. After the inert anode is adopted, CO2, CO and CFn are not emitted anymore; at the same time, the O2 emitted by the anode can be used as byproduct. Therefore, as for the electrolytic aluminum industry with high emission, the adoption of aluminum electrolysis process by using inert anode is of great importance. If the inert anode is jointly used with the wettable cathode, 20%-30% energy consumption can be reduced, improving the energy efficiency. At the same time, the design of efficient and green electrolytic cell can largely increase the production capacity of unit floor space and reduce the volume of electrolytic cell to improve the energy production efficiency, significantly reduce the investment cost and reduce the cost of primary aluminum.
An electrolytic cell with horizontal current has been published by Chinese Patent No. CN200810049240.5, Chinese Patent No. CN 89210028.1 and U.S. Pat. No. 6,866,768. However, the cell structure is only described in concept, the specific and detailed description is absent, and it is difficult to realize the aluminum production in the highly corrosive fluoride fusant by means of electrolytic cell with horizontal current.
Although the method for producing aluminum by electrolysis and the electrolytic cell for the potassium cryolite fused salt system is raised by Chinese Patent CN200510011143.3, the cell structure is only described in concept; no specific description and specific connection mode between the electrode and steam are provided; no specific method for protecting the steam and avoiding the oxidization in the high-temperature oxygen atmosphere is provided; no specific heat preservation measure is involved. An electrolytic cell with cathode groove is published by Chinese Patent CN200420060680.8 and Chinese Patent CN200510011142.9. However, the electrolytic cell with cathode groove is only aimed at the electrolytic cell for traditional aluminum electrolysis process.
An electrolytic cell with inert electrode is published by Chinese Patent CN200610051288.0. The electrolytic cell with inert electrode is an electrolytic cell, where the plate-like metal ceramic inert anode is connected in parallel with the wettable cathode and is perpendicularly and parallelly set up. However, a feasible and effective electrolytic cell for the alloy anode is not raised.
Electrolytic cells involved in above-mentioned patents are open electrolytic cells. No sealing measure is adopted, which is adverse to the oxygen collection; no specific connection mode between the electrode and the steam is provided; no specific method for protecting the steam and avoiding the oxidization in the high-temperature oxygen atmosphere is provided; no specific heat preservation measure is involved; and aluminum-free level operation can not be achieved by the cathode with groove.